This invention pertains to transparent armor systems that are subject to multiple hits by small arms fire or other projectiles. In particular, my invention provides an improved armor system for windows of structures and security vehicles that may come under potential attack by terrorists or assailants.
In the general field of ballistic armors, it is widely accepted that transparent armor plate (bullet-resistant glasses) will be used for windows of security vehicles and structures. These glasses are well known in the art and are commercially available from a variety of worldwide vendors.
The principal problem with transparent armors is that they generally incorporate glass or ceramic materials as major construction materials. These materials are either very brittle or have limited ability to withstand multiple impacts or hits from small arms projectiles. The initial impact on such materials often causes wide spread damage over a large surface area, and leaves them highly vulnerable to subsequent impacts. Thereby, an assailant may defeat a transparent armor system merely by firing into it until the accumulative damage renders the armor system ineffective. Because most modern infantry rifles have magazine capacities approaching 30 rounds, or more, this is a serious problem with sufficient risk to defeat most transparent armor systems.
My invention remedies the above mentioned vulnerability of transparent armors by the rapid deployment of an opaque armor panel after a first projectile is fired or propelled at my transparent armor system. This will be readily achieved herein by my parallel positioning of a sheet of tempered glass that is outboard of said transparent armor plate, which has the same dimensions and fits the same window opening of a structure as the transparent armor.
The tempered glass sheet functions therein as a protective cover and as a sacrificial element or sensor. When a first projectile is fired at the window by an assailant, the tempered glass will be subjected to loss of structural integrity or global failure upon impact. Depending upon its energy loss, the initial projectile may, or may not, strike the parallel planar, transparent armor plate. In effect, this event will remove the tempered glass sheet from the window opening. Then, a spring assembly, which is loaded under compression and is located under the lower edge of the opaque armor panel, will respond to the event by translating said panel through conforming guides, attached to or formed within the structure or security vehicle, to the formerly occupied position of said glass sheet. Preferably, said translation will occur in less time than the cycle rate of the threat weapon to afford maximum security.
Thereafter, said opaque armor panel will be parallel with said transparent armor plate and will protect it from any subsequently arriving projectiles. The invention as described and claimed herein is thus both efficient and effective for resisting multiple impacts from subsequently arriving projectiles. Preferably, the opaque armor panel will also be provided in the form of a shutter, or with similar means of visibility, such as view ports and slots. Occupants will thereby have the opportunity to evaluate the intent and number of assailants, the type of threat weapori, and suitable defensive measures such as escape routes.